From patchwork Mon Mar 1 16:12:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mel Gorman X-Patchwork-Id: 12110153 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-21.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 17FB9C433DB for ; Mon, 1 Mar 2021 16:15:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BE32B64DF5 for ; Mon, 1 Mar 2021 16:15:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237661AbhCAQPU (ORCPT ); Mon, 1 Mar 2021 11:15:20 -0500 Received: from outbound-smtp31.blacknight.com ([81.17.249.62]:39168 "EHLO outbound-smtp31.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237674AbhCAQN0 (ORCPT ); Mon, 1 Mar 2021 11:13:26 -0500 Received: from mail.blacknight.com (pemlinmail02.blacknight.ie [81.17.254.11]) by outbound-smtp31.blacknight.com (Postfix) with ESMTPS id 2CCA2C0B06 for ; Mon, 1 Mar 2021 16:12:02 +0000 (GMT) Received: (qmail 30566 invoked from network); 1 Mar 2021 16:12:01 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.22.4]) by 81.17.254.9 with ESMTPA; 1 Mar 2021 16:12:01 -0000 From: Mel Gorman To: Andrew Morton Cc: Chuck Lever , Jesper Dangaard Brouer , LKML , Linux-Net , Linux-MM , Linux-NFS , Mel Gorman Subject: [PATCH 5/5] net: page_pool: use alloc_pages_bulk in refill code path Date: Mon, 1 Mar 2021 16:12:00 +0000 Message-Id: <20210301161200.18852-6-mgorman@techsingularity.net> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210301161200.18852-1-mgorman@techsingularity.net> References: <20210301161200.18852-1-mgorman@techsingularity.net> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Jesper Dangaard Brouer There are cases where the page_pool need to refill with pages from the page allocator. Some workloads cause the page_pool to release pages instead of recycling these pages. For these workload it can improve performance to bulk alloc pages from the page-allocator to refill the alloc cache. For XDP-redirect workload with 100G mlx5 driver (that use page_pool) redirecting xdp_frame packets into a veth, that does XDP_PASS to create an SKB from the xdp_frame, which then cannot return the page to the page_pool. In this case, we saw[1] an improvement of 18.8% from using the alloc_pages_bulk API (3,677,958 pps -> 4,368,926 pps). [1] https://github.com/xdp-project/xdp-project/blob/master/areas/mem/page_pool06_alloc_pages_bulk.org Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Mel Gorman Reviewed-by: Ilias Apalodimas --- net/core/page_pool.c | 63 ++++++++++++++++++++++++++++---------------- 1 file changed, 40 insertions(+), 23 deletions(-) diff --git a/net/core/page_pool.c b/net/core/page_pool.c index a26f2ceb6a87..567680bd91c4 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -208,44 +208,61 @@ noinline static struct page *__page_pool_alloc_pages_slow(struct page_pool *pool, gfp_t _gfp) { + const int bulk = PP_ALLOC_CACHE_REFILL; + struct page *page, *next, *first_page; unsigned int pp_flags = pool->p.flags; - struct page *page; + unsigned int pp_order = pool->p.order; + int pp_nid = pool->p.nid; + LIST_HEAD(page_list); gfp_t gfp = _gfp; - /* We could always set __GFP_COMP, and avoid this branch, as - * prep_new_page() can handle order-0 with __GFP_COMP. - */ - if (pool->p.order) + /* Don't support bulk alloc for high-order pages */ + if (unlikely(pp_order)) { gfp |= __GFP_COMP; + first_page = alloc_pages_node(pp_nid, gfp, pp_order); + if (unlikely(!first_page)) + return NULL; + goto out; + } - /* FUTURE development: - * - * Current slow-path essentially falls back to single page - * allocations, which doesn't improve performance. This code - * need bulk allocation support from the page allocator code. - */ - - /* Cache was empty, do real allocation */ -#ifdef CONFIG_NUMA - page = alloc_pages_node(pool->p.nid, gfp, pool->p.order); -#else - page = alloc_pages(gfp, pool->p.order); -#endif - if (!page) + if (unlikely(!__alloc_pages_bulk_nodemask(gfp, pp_nid, NULL, + bulk, &page_list))) return NULL; + /* First page is extracted and returned to caller */ + first_page = list_first_entry(&page_list, struct page, lru); + list_del(&first_page->lru); + + /* Remaining pages store in alloc.cache */ + list_for_each_entry_safe(page, next, &page_list, lru) { + list_del(&page->lru); + if (pp_flags & PP_FLAG_DMA_MAP && + unlikely(!page_pool_dma_map(pool, page))) { + put_page(page); + continue; + } + if (likely(pool->alloc.count < PP_ALLOC_CACHE_SIZE)) { + pool->alloc.cache[pool->alloc.count++] = page; + pool->pages_state_hold_cnt++; + trace_page_pool_state_hold(pool, page, + pool->pages_state_hold_cnt); + } else { + put_page(page); + } + } +out: if (pp_flags & PP_FLAG_DMA_MAP && - unlikely(!page_pool_dma_map(pool, page))) { - put_page(page); + unlikely(!page_pool_dma_map(pool, first_page))) { + put_page(first_page); return NULL; } /* Track how many pages are held 'in-flight' */ pool->pages_state_hold_cnt++; - trace_page_pool_state_hold(pool, page, pool->pages_state_hold_cnt); + trace_page_pool_state_hold(pool, first_page, pool->pages_state_hold_cnt); /* When page just alloc'ed is should/must have refcnt 1. */ - return page; + return first_page; } /* For using page_pool replace: alloc_pages() API calls, but provide